/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package iped.parsers.fork;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.ref.WeakReference;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLStreamHandler;
import java.net.URLStreamHandlerFactory;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;

class MemoryURLStreamHandlerFactory implements URLStreamHandlerFactory {

    public URLStreamHandler createURLStreamHandler(String protocol) {
        if ("tika-in-memory".equals(protocol)) {
            return new MemoryURLStreamHandler();
        } else {
            return null;
        }
    }

    public static class MemoryURLStreamHandler extends URLStreamHandler {

        private static final AtomicInteger counter = new AtomicInteger();

        private static final List<MemoryURLStreamRecord> records = new LinkedList<MemoryURLStreamRecord>();

        public static URL createURL(byte[] data) {
            try {
                int i = counter.incrementAndGet();
                URL url = new URL("tika-in-memory", "localhost", "/" + i);

                MemoryURLStreamRecord record = new MemoryURLStreamRecord();
                record.url = new WeakReference<URL>(url);
                record.data = data;
                records.add(record);

                return url;
            } catch (MalformedURLException e) {
                throw new RuntimeException(e);
            }
        }

        @Override
        protected URLConnection openConnection(URL u) throws IOException {
            Iterator<MemoryURLStreamRecord> iterator = records.iterator();
            while (iterator.hasNext()) {
                MemoryURLStreamRecord record = iterator.next();
                URL url = record.url.get();
                if (url == null) {
                    iterator.remove();
                } else if (url == u) {
                    return new MemoryURLConnection(u, record.data);
                }
            }
            throw new IOException("Unknown URL: " + u);
        }

        public static class MemoryURLStreamRecord {

            public WeakReference<URL> url;
            public byte[] data;

        }

        public static class MemoryURLConnection extends URLConnection {

            private final byte[] data;

            MemoryURLConnection(URL url, byte[] data) {
                super(url);
                this.data = data;
            }

            @Override
            public void connect() {
            }

            @Override
            public InputStream getInputStream() {
                return new ByteArrayInputStream(data);
            }

        }

    }

}